Tamper-evident locking device

ABSTRACT

The lockable tamper-evident device is suitable for securing a closure member in its closed position to an article. The device comprises a pair of arms (1,1&#39;) which are movable between an open position in which the arms (1,1&#39;) are engagable with an article and/or a closure member, and a locked-closed position in which disengagement of the arms from the article and/or the closure member is prevented by engagement of a cooperable locking means. 
     Preferably, the arms (1,1&#39;) are engagable with a projection 7,7&#39; extending either from the article and through an opening in the closure member or from the closure member and through an opening in the article. 
     Preferably, the cooperable locking means (8,10,11,12) is carried by the arms (1,1&#39;), activation of the locking means (8,10,11,12) being brought about by movement of the arms (1,1&#39;) to the locked-closed position. In the locked-closed position removal of the closure member is prevented by engagement of the arms (1,1&#39;) with the article and/or the closure member.

This invention relates to a locking device and in particular to alockable, tamper-evident device for securing a closure member in itsclosed position to an article.

Conventionally, locking devices necessitate the use of a tool, forexample a key, for locking and/or unlocking purposes. With such locksunauthorised opening and subsequent locking is not always evident andpotential duplication of the tool provides an additional security risk.Further problems associated with these locks would be apparent to theskilled person and include: accidental loss of the key necessitatingbreakage of the lock; the wear and tear of the engagable and movableparts of the lock and key; and the expense and maintenance of the lock.

U.S. Pat. No. 5,522,627 discloses a reusable security seal. The sealcomprises a pair of hingedly-mounted arms having co-operable lockingmeans located at the free ends of the arms. Locking of the seal iseffected by hinged movement of the arms towards each other andengagement of the co-operable locking means.

DE-A-1761379 discloses a seal which is operable in a similar manner tothe one disclosed in U.S. Pat. No. 5,522,627. However, in this case eachof the hingedly-mounted arms has a recess which, when the device is inthe locked-closed position, cooperate to trap and retain a cord orribbon.

The present invention overcomes the above problems by providing a cheapto produce and reliable, lockable device for which no separate tool isrequired for locking and/or unlocking purposes. The device provides aself-evident means for identifying when a closure member for an articlehas been tampered with in order to gain access to the article. Once thedevice is in a locked-closed position it is only removable by meanswhich result in physical damage to the device which in turn providesevidence of tamper. Furthermore, once the device has assumed thelocked-closed position it is not re-usable. Thus, it may be moreappropriate to refer to the lockable device as a security seal. Eachseal is uniquely identifiable, for example, by a bar code or serialnumber or by other means which would be apparent to the skilled person.Accordingly, any attempted replacement of a broken seal with a new sealwould be evident by comparison of the respective device identificationmeans.

The present invention provides a lockable tamper-evident device forsecuring a closure member in its closed position to an article,comprising a pair of arms mounted by a hinge to each other which armsare movable along a defined radial path relative to the hinge between anopen position wherein the free ends of the arms remote from the hingeare spaced apart from each other thereby permitting respectiveoutwardly-facing portions of the arms to engage with the article and/orclosure member, and a locked-closed position in which disengagement ofthe arms from the article and/or the closure member is prevented byengagement of a co-operable locking means carried by the arms,activation of the locking means being brought about by radial movementof the arms towards each other and into the locked-closed position, andwhen in the locked-closed position removal of the closure member beingprevented by engagement of the arms with the article and/or the closuremember.

In one embodiment of the present invention, the arms are engagable witha projection extending either from the article and through an opening inthe closure member or from the closure member and through an opening inthe article. In the latter embodiment, the projection may extend throughan opening provided in an outwardly facing part of the article.

The projection and the arms are adapted to engage with each other. In apreferred embodiment, the arms form a socket in the locked-closedposition which is engagable with a ball located at the free end of theprojection. Alternatively, the arms may carry inwardly facing edgeswhich, in the locked-closed position, grip corresponding grooves locatedon the projection. Preferably, the projection and the correspondingopening are of non-circular cross section to minimise potential rotationof the closure member about the projection. The present inventionincludes further means for engagement of the arms and the projectionwhich would be apparent to the skilled person.

Preferably the arms are simultaneously engagable, when in the openposition, with two projections and when in the locked-closed positionthe cooperable locking means prevents disengagement of the arms from thetwo projections.

In a preferred embodiment, each arm carries an outwardly extendingportion, and when the arms are in the locked-closed position, theoutwardly extending portions protrude in substantially oppositedirections, and when the arms are in the open position, said portionsare engagable with corresponding orifices located on facing surfaces ofthe two projections. In a more preferred embodiment, the two projectionshave a pair of holes located in facing surfaces for engagement with theoutwardly extending portions of the arms.

In one embodiment the arms are hingeable and the outwardly extendingportions protrude from the outer surface of each arm which is remotefrom the hinge. In a more preferred embodiment, the arms are hingeableend-to-end and the outwardly extending portions are located in closeproximity to the hingeable ends of the arms. In the latter embodiment,the distance between the respective free ends of the outwardly extendingportions is greater in the locked-closed position than it is in the openposition. This is achievable by way of the hingeable arrangement of thearms which is described below. In the locked-closed position, the armsare substantially parallel to each other and the internal angle formedby the arms and the hinge is substantially zero. As the internal angleis increased by hinged movement of the arms, the free ends of theoutwardly extending portions follow a defined radial path relative tothe hinge. At a given internal angle, the free ends of the outwardlyextending portions will be diametrically opposite each other at whichpoint the distance between the free ends is a maximum. Further hingedmovement increases the internal angle and simultaneously reduces thedistance between the respective free ends of the arms until the armsreach the open position in which they are engagable with the twoprojections. In principle, the maximum internal angle between the armsis limited by abutment of the hingeable ends of the arms with eachother. However, the maximum internal angle is generally restricted toless than 180° by cooperation of an abutment shoulder extending from thehingeable end of one arm with the hingeable end of the other arm.Restriction of the internal angle reduces undesirable stress on thehinge.

One or both of the two projections may be slidably mountable to thearticle and/or the closure member. In this embodiment the outwardlyextending portions are barbed so that, following engagement of theoutwardly extending portions with the two projections, inadvertentdisengagement of an outwardly extending portion from its projection doesnot occur as a result of slidable movement of the projection/s. Anadvantage of this embodiment is that the barbed portions automaticallyprovide a tightening of the device and the article and/or the closuremember during actuation of the arms from the open position to thelocked-closed position by a relative drawing together of the twoprojections.

According to a preferred embodiment of the present invention, one of thearms of the device has a line of weakness located between the lockingmeans and the point of engagement of the arm with the projection, saidline of weakness providing convenient means for removal of the device.Simple manual force, for example fingers acting directly on the arm, issufficient to break the arm and release the seal.

In one embodiment, the device is simultaneously engagable with aprojection extending from the closure member and with a projectionextending from the article. In this embodiment, the closure member ispreferably mountable to the article at a position away from the point ofengagement of the device and the two projections.

Reference is now made to the accompanying drawings without anylimitation thereto being intended.

FIG. 1 illustrates a plan view of one embodiment of the device accordingto the present invention in which the arms are in the open position andin which the arms are engagable with two projections.

FIG. 2 illustrates a plan view of the device as shown in FIG. 1 in whichthe arms are in the locked-closed position.

FIG. 3 illustrates a plan view of the device as shown in FIG. 2 in whichone of the arms has been broken along a line of weakness to allowremoval of the device.

Referring to FIG. 1, a pair of arms 1,1' are mounted end-to-end by ahinge 2. The arms and hinge are formed as an integral plastics mounding.Each arm 1,1' carries a curved outwardly extending portion 3,3' locatedon the outer surface 4,4' of each arm 1,1' which is remote from thehinge 2. The arms 1,1' are movable along a defined radial path relativeto the hinge 2. At a given position, identified by the line A, the freeends 5,5' of the curved portions 3,3' are diametrically opposite eachother. In this position, the distance between the respective free ends5,5' is a maximum. Any further increase of the internal angle, φ, formedby the arms 1,1' and the hinge 2, reduces the distance between therespective free ends 5,5' of the curved portions 3,3' until an openposition is achieved in which the curved portions 3,3' are engagablewith a pair of openings 6,6' located in facing surfaces of a pair ofcorresponding projections 7,7' forming part of the article (not shown)to be secured. The projections 7,7' are of rectangular cross-section andextend through corresponding rectangular slots provided in the closuremember (not shown). Only the free ends of the projections 7,7' areillustrated.

A resiliently yieldable arrow-head formation 8 is located on the insidesurface 9 of the arm 1. Hinged actuation of the arms 1,1' (in thedirection of the arrows) towards each other permits sliding insertion ofthe arrow-head formation 8 through a reduced diameter mouth 10 locatedon the facing inside surface 9' of the arm 1' and into a correspondingsocket 11 located within the arm 1'. The reduced diameter mouth 10defines an inwardly facing abutment shoulder 12. Following insertion ofthe arrow-head formation 8 into the socket 11, retraction of thearrow-head formation 8 is prevented by abutment of the arrow-headformation 8 with the shoulder 12 of the reduced diameter mouth 10. Thisrepresents the closed-locked position of the arms 1,1'.

During actuation of the arms 1,1' from the open position to theclosed-locked position, the curved portions 3,3' tend to pull theprojections 7,7' together thereby tightening the lockable assembly.

The arm 1' carries a protective flange 13 along both opposite sidesurfaces (not shown) of the arm 1' (only one is shown). During actuationof the arms 1,1' to the locked-closed position, the flanges 13 slideover the corresponding opposite side surfaces (not shown) of the arm 1and protect the arrow-head formation 8, the reduced diameter mouth 10,the abutment shoulder 12 and the socket 11 from tamper.

FIG. 1 also illustrates a single barb variant 14 which isinter-changeable with the arrow-head formation 8 on arm 1. Followingactuation of the arms 1,1' from the open position to the locked-closedposition the single barb 14 is slidingly inserted into, though notretractable from the corresponding reduced diameter mouth 15 located onthe inside surface 9' of the arm 1'. The abutment shoulder 16 and thesocket 17 function as described above for the shoulder 12 and the socket11 respectively.

An extension 18 of the hinged end 19' of the arm 1' provides an abutmentsurface 20. The surface 20 prevents excess hinged movement of the arms1,1' by abutment of the hinged end 19 of the arm 1 with the surface 20.

Referring to FIG. 2, the arms 1,1' are in the locked-closed position.The barbed portions 3,3' are engaged with the projections 7,7' and thearrow-head formation 8 is non-retractably inserted into the socket 11located in the arm 1'. A line of weakness 21 is located across the arm1' between the barbed portion 3' and the socket 12.

Referring to FIG. 3, the arm 1' has been broken along the line ofweakness 21, thereby allowing the barbed portions 3,3' to hinge towardseach other to an open position in which they are releasable from theopenings 6,6' of the projections 7,7'. The illustrated device is nowbroken, unusable and provides evidence of tamper. In practice, thedevice is only intended to be broken by authorised personnel.

What is claimed is:
 1. A lockable tamper-evident device for securing aclosure member in its closed position, comprising a pair of armshingedly linked to each other at respective proximal ends, so as topermit movement of one arm relative to the other through an arc betweenan open position, in which distal ends of the arms are spaced apart, anda closed position, in which the distal arm ends abut each other, eacharm having an abutting surface and an opposite non-abutting surface,wherein the respective abutting surfaces abut each other in the closedposition, and each non-abutting surface having a hook for engagementwith the closure member to be secured, the spacing apart of the hooksbecoming greater during movement from the open position to the closedposition, and the abutting surface of one arm having a plug and theabutting surface of the other arm having a socket for receiving andnon-detachable permanent locking of the plug in the closed position. 2.A device according to claim 1, wherein in the open position the arms aresimultaneously engageable with two projections forming part of theclosure member and wherein in the closed position disengagement of thearms from the two projections is prevented by the permanent locking ofthe plug in the socket.
 3. A device according to claim 2, wherein, whenthe arms are in the closed position, the hooks protrude in substantiallyopposite directions, and when the arms are in the open position, saidhooks are engageable with a pair of orifices located on facing surfacesof the two projections.
 4. A device according to claim 3, wherein atleast one of the hooks is curved such that, when in the closed position,the free end of the curve points away from the proximal end andgenerally towards the distal end of the respective arm.
 5. A deviceaccording to claim 1 wherein one of the arms carries a line of weaknesslocated between the plug or socket and the hook, said line of weaknessproviding means for easy release of the device by authorized personnel.6. A device according to claim 1, wherein in the closed position theplug and socket are externally inaccessible.
 7. A device according toclaim 1, wherein in the locked-closed position the co-operable lockingmeans is externally inaccessible.